Electro-fluidic/hydrofluidic transducer

ABSTRACT

This transducer has a fluidic amplifier with a fluid beam forming nozzle in spaced relation from output ports and a pin movable in the space between the nozzle and output ports to vary the fluid flow from the nozzle through the output ports and eventually in portions of a fluid system connected therewith. An electromagnetic means is provided to move the pin in proportion to electric signals supplied to the electromagnetic means, the latter having a pivotally mounted element for supporting the pin. The pin supporting element has a coil assembly arranged in a magnetic field, electrical signals being introduced to the coil assembly to effect movement of the pin. Such movement varies the pressure output from the transducer to control actuator components of pneumatic or hydraulic systems.

United States Patent Chapin ELECTRO-FLUlDlC/HYDROFLUIDIC TRANSDUCER [75] Inventor: Donald W. Chapin, Scottsdale, Ariz.

[73] Assignee: The Garrett Corporation, Los

Angeles, Calif.

[22] Filed: Oct. 9, 1973 [21] App]. No.: 404,470

[52] US. Cl. 137/83; 137/83]; 335/276 [51] Int. Cl. F15C 3/14 [58] Field of Search 137/831, 625.61, 625.62, 137/83, 625.64; 335/274, 276

[56] References Cited UNITED STATES PATENTS 3,165,676 1/1965 OBrien 335/276 X 3,304,524 2/1967 Zoltan 335/274 X 3,612,103 10/1971 Waddington 137/625.64 X

3,638,671 2/1972 Harvey et al. 137/831 3,714,610 1/1973 Duff et al 335/274 X Primary Examiner-William R. Cline Attorney, Agent, or Firml-lerschel C. Omohundro; Jack D. Puffer; Albert .1. Miller [57] ABSTRACT This transducer has a fluidic amplifier with a fluid beam forming nozzle in spaced relation from output ports and a pin movable in the space between the nozzle and output ports to vary the fluid flow from the nozzle through the output ports and eventually in portions of a fluid system connected therewith. An electromagnetic means is provided to move the pin in proportion to electric signals supplied to the electromagnetic means, the latter having a pivotally mounted element for supporting the pin. The pin supporting element has a coil assembly arranged in a magnetic field, electrical signals being introduced to the coil assembly to effect movement of the pin. Such movement varies the pressure output from the transducer to control actuator components of pneumatic or hydraulic systems.

8 Claims, 9 Drawing Figures l II V l \I! 38 '\'l ffa-llzaz 24 i 2 3 7 ,2; 22o-\ 25 25 K 2| 27 g; QI ,21

I4 H E I8 13 US Patent Sept. 23,1975 Sheet 1 052 3,906,979

FIG.3.

US Patent Sept. 23,1975

Sheet 2 of 2 PIC-5.9.

ELECTRO-FLUIDIC/HYDROFLUIDIC TRANSDUCER BACKGROUND OF THE INVENTION This invention relates generally to control systems and is more particularly directed to pilot devices of control systems in which minute signals, of either electrical or fluid pressure type, are translated into strong control impulses for ultimate actuating devices. More specifically, the invention relates to the class of structures exemplified by the following patents to which attention is respectively directed. US. Pat. Nos. 3,102,389 to Pederson et al; 3,187,762 to Norwood; 3,209,775 to Dexter et a]; 3,258,024 to Bauer; 3,275,014 to Plasko; 3,276,463 to Bowles; 3,276,473 to Lewis et a1; 3,470,914 to Smith; 3,509,775 to Evans; and 3,638,671 to Harvey et al. These patents show various types of control elements which while capable of suitable operation have certain objectionable features, such as complicated constructions, high vibration when in operation, sensitivity to extreme temperatures, hysteresis, excessive weight, etc, which the present combination of elements has been designed to overcome.

SUMMARY OF THE INVENTION As indicated above, this invention relates generally to control systems and more particularly to certain components of fluid pressure systems utilized to receive signals and transmit modified forms thereof to other components, such as actuators, of the systems.

An object of this invention resides in providing an electrofluidic transducer in which signals of one type, such as electrical signals, are transformed into signals of another type, such as pneumatic, and modified in a manner to render them more effective or suitable for the performance of desired objectives.

Another object of this invention is to provide a trans ducer having a fluidic amplifier and an electromagnetic device for controlling the operation of the amplifier in accordance with electrical signals supplied to the transducer by a structure of a character suitable for sensing a condition in a mechanism whereby operations of the mechanism relative to such condition may be initiated or controlled.

A further object of the invention is to provide a transducer having a fluidic amplifier in which fluid pressure signals, bearing a predetermined relation to electrical signals supplied to the transducer, are produced through the use of structure designed to-move in a manner to eliminate hysteretie losses.

A still further object of the invention is to provide a transducer having a fluidic amplifier in which a fluid beam is diverted, in proportion to electrical signals supplied to the transducer, by an element which swings back and forth relative to the fluid beam in response to the electrical signals.

An object also is to provide a transducer having a fluidic amplifier in which a fluid beam is diverted by an element forming part of an electromagnetic device, the element being attached to an assembly supported in a magnetic field for movement about an axis extending parallel to the beam, the assembly including a coil to which electrical signals are applied.

A further object of the invention is to provide a transducer of the type referred to in the three preceding paragraphs with a particular mounting for the coil assembly including the swinging member, the mounting being a friction-free pivotal structure which will give consistent results with minimum hysteresis and be unaffected by vibration or high temperatures.

With the foregoing and other objects in view, which will become apparent as the description proceeds, the invention herein resides in the construction and relation of parts more particularly pointed out in the following portion of this specification.

THE DRAWINGS FIG. 1 is a perspective view of an electro-fluidie transducer formed in accordance with the present invention;

FIG. 2 is a vertical longitudinal sectional view of the transducer shown in FIG. 1;

FIG. 3 is a similar view taken through the transducer on the plane indicated by the line Ill-III of FIG. 2;

FIG. 4 is a detail sectional view taken on the plane indicated by the line I\/lV of FIG. 3;

FIG. 5 is a horizontal sectional view taken on the plane indicated by the line \/--V of FIG. 3;

FIG. 6 is a perspective view of a deflecting pin supporting coil assembly used in the transducer shown in FIG. 1; and

FIGS. 7, 8, and 9 are enlarged detail sectional views illustrating one form of friction-free pivot which may be used to movably mount the coil assembly depicted in FIG. 6.

DESCRIPTION More particular reference to the drawings will show that a transducer 10 embodying the invention includes two major parts 11 and 12. the former being a fluidic amplifier and the latter an electromagnetic actuator means. The amplifier l I may be of many forms, the one selected for illustration having a body composed of a plurality of metal laminations with openings cooperating when the laminations are secured in stacked order, to form a chamber 13, an inlet port 14, a nozzle opening 15 leading from the inlet port 14 into the chamber at one side, a plurality of outlet ports 16 communicating with the chamber at the opposite side, and one or more vent ports leading from the chamber at suitable locations to the atmosphere or other region of low pressure. It will be obvious to those familiar with the art that in operation, fluid under pressure supplied to the inlet port 14 will issue from the nozzle opening in the form of a fluid beam and, if not interrupted in some manner, will pass across the chamber 13 and be directed into parts of a fluid system through the outlet ports 16. These ports are connected in a suitable manner with the system under control by the transducer. In the form of amplifier illustrated, the axis XX of the nozzle opening is aligned with a pointed projection 17 which separates the outlet ports 16. Obviously other arrangements of outlets could be employed if desired.

To vary the portions of the fluid beam flowing into the different outlet ports and consequently the sections of the system connected therewith, a pin 18 is projected into the chamber 13 to engage and deflect variable portions of the fluid beam into or away from one or the other of the outlet ports. The pin 18 may be normally positioned in the axis XX or on either side thereof depending upon the functions of the amplifier. By moving the pin to one side of the axis XX and then to the other the portions of the fluid beam directed to the ports 16 will be varied. In this manner fluid pressures in such outlet ports will consequently be varied.

Movement of the pin 18 is effected by the operation of the electromagnetic actuator means 12. This means has a mounting plate 20 secured to the amplifier 11. Plate 20 is provided on opposite side edges with lugs 21, bored to receive pivot members 22 and slotted as at 23 (see FIG. 4) so that the pivot members can be clamped at the outer ends 22a thereof in proper position on the mounting plate by screws 24. The inner ends 25 of the pivot members are fixed in the ends of a supporting member 26 from which pin 18 projects. As shown particularly in H0. 6, the pin supporting member 26 is in the nature of a frame 27 with spaced outwardly projecting flanges 27:! at the sides and ends, the inner ends 25 of the pivots being disposed and secured between the flanges at the ends of the frame 27.

To secure certain of the objects recited above, the pivot members 22 are constructed in a special manner and are of the Cardan hinge" type which are friction free in that there is no rolling, sliding or rubbing contact between the parts. One type of pivot construction is shown in H05. 7, 8, and 9. This type includes inner and outer end pieces 25 and 2211, respectively, which are of tubular form arranged in spaced end to end relation. End pieces 22a and 25 surround a central tube 28 in which a plurality of leaf elements 29 are disposed. These elements are arranged edge to edge and at right angles to each other when viewed from the end of the pivot, as in FIGS. 8 and 9. Each leaf element 29 is secured at one end 29a to either end piece 22a or 25 and at the opposite end to central tube 28. The latter tube has openings 30 through which the leaf element ends 29a pass to engage and be secured to the end pieces 22:! and 25. It will be understood from the description above, taken in connection with FIGS. 7, 8, and 9, that limited relative rotary movement between the inner and outer end pieces 25 and 22a of the pivot may take place without friction due to rolling. sliding or rubbing contact as occurs in customary pivots and bearings. All flexing of the leaf elements. necessary to provide the required movement of the pin 18 will be minor in extent and the spring rate may be precisely calculated and compensated for in the construction of the pivots and the power employed during operation. With the type of pivot described and illustrated losses due to hysteresis are minimized.

Prior to the insertion of the inner ends 25 of the pivots into the frame 27, a coil 31 is wound around the frame between the flanges 2711. This coil is wound in such a manner that when the member is installed with the pivots in the lugs 21. the coil will be substantially horizontal, i.e., with the axis of the coil coinciding with the axis of the pin 18 and extending through the axis XX of the nozzle opening and at right angles thereto. The ends of the coil are electrically connected with the inner ends of the pivots; leads 32 are connected with the outer ends of the pivots.

The space within the frame 27 surrounded by the coil 31 receives a center pole 33 of the electromagnetic means 12. Pole 33 is formed of soft iron and is brazed to a threaded block 34 which is also brazed to a pair of soft iron side poles 35 located with one on each side of the axis of the pivots 22 and center pole 33. The side poles are secured by screws 36 to the mounting plate 20. This arrangement retains the center pole 33 stationary in the region surrounded by the pin supporting member 26 and coil assembly. The electromagnetic means 12 is completed by an inverted U-shaped permanent magnetic 37 which is secured with the ends of the legs of the U-shape in engagement with the side poles 34. A screw 38 extends through a central opening in the magnet and is threaded into the block 34 to maintain the parts of the electromagnetic means 12 in assembled relation.

The leads 32 extend from the outer ends of the pivots 22 to the exterior of a cover for connection with an electrical coupling 41 mounted on the end of the cover which is designated by the numeral 40. Signals from a suitable sensor system are supplied to the coupling 41 to effect the operation of the transducer.

In the operation of the device, the signals energize the coil 31 producing a flux which is primarily in air and reacts with the magnetic field of the magnet tending to revolve the coil assembly, including the member 26 and pin 18 supported thereby, about the axis of the pivots 22. This revolving or rocking movement of the coil assembly and pin moves the latter in or through the fluid beam flowing from the nozzle 15 and deflects part of the beam away from the output ports to vary the fluid pressure in the portions of the fluidic system connected therewith.

it should be noted that the axis of the pivot members 22 is substantially parallel with the axis XX of the nozzle opening 15 of the fluidic amplifier. The mounting of the pin 18 and supporting member 26 therefor is such that the pin revolves or swings about the axis of the pivots and in or through the fluid beam to deflect varying portions of the beam into and away from the output ports. The movable portions of the electrofluidic transducer are light in weight and mounted to respond to extremely low forces, Hysterctic losses are thus minimized and a low cost structure results. The structure is relatively insensitive to vibration and can withstand relatively high temperatures.

in the event it is found necessary suitable counterbalancing means 42 may be added to the pin supporting member to eliminate vibration and increase accuracy. Since the pin, the frame 27, and coil 31 are relatively small, the unbalanced portion thereof will be lightweight requiring the counterbalance 42 to be of minimum size and mass.

I claim:

1. An electro-fluidic transducer comprising:

a. a fluidic element having a nozzle opening receiving fluid from a pressure source and forming a fluid beam. said element also having an output port dis posed in spaced registering relationship with said nozzle opening to receive said fluid beam;

b. an electromagnetic means secured to said fluidic element and having a member supported by a pair of flex pivots for rotary movement about an axis substantially parallel to that of the beam formed by said nozzle and at one side thereof. said electromagnetic means comprising a side pole on either side of the axis of rotation of said member and a center pole piece substantially coaxial with said axis and having a coil encircling said center pole piece with the axis of the coil at right angles to the axis of the pivots, said member being moved in response to signals applied to said coil; and

c. a pin supported by said members and extending into the space between said nozzle opening and output port, rotary movement of said member serving to swing said pin across the path of said beam to vary the portion thereof flowing through said output port.

2. The electro-fluidic transducer of claim 1 in which the electromagnetic means has a U-shaped permanent magnet mounted with the ends of the legs of the U- shape in engagement with said side poles.

3. The electro-fluidic transducer of claim 1 in which the pin supporting member has means for counterbalancing the coil to eliminate vibration.

4. An electro-fluidictransducer comprising:

a. a fluidic element having a nozzle opening receiving fluid from a pressure source and forming a fluid beam, said element also having an output port disposed in spaced registering relationship with said nozzle opening to receive said fluid beam;

b. an electromagnetic means comprising;

1. a mounting plate secured to the fluidic element,

said mounting plate having spaced lugs;

2. pivot means carried by said spaced lugs, said pivot means supporting a member for rotary movement about an axis substantially parallel to that of the beam formed by the nozzle of said flu idie element, said member being moved about said axis in response to signals applied to said electromagnetic means;

3. a pair of pole pieces disposed with one on each side of the axis of rotary movement of said member;

4. a magnet with poles engaging said pole pieces;

5. a coil assembly on said member; and

6. a center pole piece encircled by the coil of said coil assembly, said center pole piece being secured to said magnet and said pair of pole pieces;

c. a pin supported by said member and extending into the space between said nozzle opening and output port, rotary movement of said member serving to swing said pin across the path of said beam to vary the portion thereof flowing through said output port.

5. The electro-fluidic transducer of claim 4 in which the pivot means includes spaced inner and outer end pieces connected for limited relative rotary movement by a plurality of flexible leaf elements disposed edge to edge and in angular relation to each other about the axis of the pivot means.

6. The electro transducer of claim 5 wherein the signals applied to said electromagnetic means are applied to the coil of said coil assembly through the flexible leaf elements of said pivot means.

7. An electro-fluidic transducer comprising:

a base member having a planar surface and spaced apart upright legs thereon, said planar surface having a generally central opening therein;

a fluidic member mounted on said base on the surface opposite the surface carrying said legs, said fluidic element having a fluid input port and at least one fluid output port, said input and output ports being connected by conduit means having a nozzle in registry with said output port, the area between said nozzle and said output port being in registry with the central opening in said base member;

electromagnetic means mounted on said base plate, one portion of said electromagnetic means being fixed to said base means and another portion of said electromagnetic means being mounted on said upright legs for rotary movement about an axis substantially parallel to the axis of the conduit means of said fluidic member in response to control signals applied to the rotatively movable portion of said electromagnetic means;

a pair of pivot means connecting the movable portion of said electromagnetic means with each of said upright legs, said pivot means supporting the movable portion of said electromagnetic means for rotary movement and connecting said last named means to the source of said control signals; and

pin means mounted on said rotary portion of said electromagnetic means for rotation therewith, said pin means extending through the central opening on said base means and into the area of said fluidic means between the nozzle and said output port.

8. The electro-fluidic transducer of claim 7 wherein each of said pivot means includes spaced inner and outer end pieces connected for limited relative rotary movement by a plurality of flexible leaf elements disposed edge to edge and in angular relation to each other about the axis of the pivot means.

l l =l 

1. An electro-fluidic transducer comprising: a. a fluidic element having a nozzle opening receiving fluid from a pressure source and forming a fluid beam, said element also having an output port disposed in spaced registering relationship with said nozzle opening to receive said fluid beam; b. an electromagnetic means secured to said fluidic element and having a member supported by a pair of flex pivots for rotary movement about an axis substantially parallel to that of the beam formed by said nozzle and at one side thereof, said electro-magnetic means comprising a side pole on either side of the axis of rotation of said member and a center pole piece substantially coaxial with said axis and having a coil encircling said center pole piece with the axis of the coil at right angles to the axis of the pivots, said member being moved in response to signals applied to said coil; and c. a pin supported by said members and extending into the space between said nozzle opening and output port, rotary movement of said member serving to swing said pin across the path of said beam to vary the portion thereof flowing through said output port.
 2. pivot means carried by said spaced lugs, said pivot means supporting a meMber for rotary movement about an axis substantially parallel to that of the beam formed by the nozzle of said fluidic element, said member being moved about said axis in response to signals applied to said electromagnetic means;
 2. The electro-fluidic transducer of claim 1 in which the electromagnetic means has a U-shaped permanent magnet mounted with the ends of the legs of the U-shape in engagement with said side poles.
 3. The electro-fluidic transducer of claim 1 in which the pin supporting member has means for counterbalancing the coil to eliminate vibration.
 3. a pair of pole pieces disposed with one on each side of the axis of rotary movement of said member;
 4. a magnet with poles engaging said pole pieces;
 4. An electro-fluidic transducer comprising: a. a fluidic element having a nozzle opening receiving fluid from a pressure source and forming a fluid beam, said element also having an output port disposed in spaced registering relationship with said nozzle opening to receive said fluid beam; b. an electromagnetic means comprising;
 5. a coil assembly on said member; and
 5. The electro-fluidic transducer of claim 4 in which the pivot means includes spaced inner and outer end pieces connected for limited relative rotary movement by a plurality of flexible leaf elements disposed edge to edge and in angular relation to each other about the axis of the pivot means.
 6. a center pole piece encircled by the coil of said coil assembly, said center pole piece being secured to said magnet and said pair of pole pieces; c. a pin supported by said member and extending into the space between said nozzle opening and output port, rotary movement of said member serving to swing said pin across the path of said beam to vary the portion thereof flowing through said output port.
 6. The electro transducer of claim 5 wherein the signals applied to said electromagnetic means are applied to the coil of said coil assembly through the flexible leaf elements of said pivot means.
 7. An electro-fluidic transducer comprising: a base member having a planar surface and spaced apart upright legs thereon, said planar surface having a generally central opening therein; a fluidic member mounted on said base on the surface opposite the surface carrying said legs, said fluidic element having a fluid input port and at least one fluid output port, said input and output ports being connected by conduit means having a nozzle in registry with said output port, the area between said nozzle and said output port being in registry with the central opening in said base member; electromagnetic means mounted on said base plate, one portion of said electromagnetic means being fixed to said base means and another portion of said electromagnetic means being mounted on said upright legs for rotary movement about an axis substantially parallel to the axis of the conduit means of said fluidic member in response to control signals applied to the rotatively movable portion of said electromagnetic means; a pair of pivot means connecting the movable portion of said electromagnetic means with each of said upright legs, said pivot means supporting the movable portion of said electromagnetic means for rotary movement and connecting said last named means to the source of said control signals; and pin means mounted on said rotary portion of said electromagnetic means for rotation therewith, said pin means extending through the central opening on said base means and into the area of said fluidic means between the nozzle and said output port.
 8. The electro-fluidic transducer of claim 7 wherein each of said pivot means includes spaced inner and outer end pieces connected for limited relative rotary movement by a plurality of flexible leaf elements disposed edge to edge and in angular relation to each other about the axis of the pivot means. 